| 1. |
- Covaciu, Lucian, 1964-, et al.
(författare)
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Brain temperature in healthy volunteers subjected to intranasal cooling
- 2011
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Ingår i: Intensive Care Medicine. - : Springer Science and Business Media LLC. - 0342-4642 .- 1432-1238. ; 37:8, s. 1277-1284
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Purpose: Intranasal cooling can be used to initiate therapeutic hypothermia. However, direct measurement of brain temperature is difficult and the intra-cerebral distribution of temperature changes with cooling is unknown. The purpose of this study was to measure the brain temperature of human volunteers subjected to intranasal cooling using non-invasive magnetic resonance (MR) methods.Methods: Intranasal balloons catheters circulated with saline at 20 °C were applied for 60 min in 10 healthy, unsedated volunteers. Brain temperature changes were measured and mapped using MR spectroscopic imaging (MRSI) and phase-mapping techniques. Heart rate and blood pressure were monitored throughout the experiment. Rectal temperature was measured before and after the cooling. Mini Mental State Examination (MMSE) test and nasal inspection were done before and after the cooling. Questionnaires about the subjects personal experience were filled after the experiment.Results: Brain temperature decrease measured by MRSI was -1.7 ± 0.8°C and by phase-mapping -1.8 ± 0.9°C at the end of cooling. Spatial distribution of temperature changes was relatively uniform. Rectal temperature decreased by -0.5 ± 0.3°C. The physiological parameters were stable and no shivering was reported. The volunteers remained alert during cooling and no cognitive dysfunctions were apparent at MMSE test. Postcooling nasal examination detected increased nasal secretion in 9 of the 10 volunteers. Volunteer’s acceptance of the method was good. Conclusion: Both MR techniques revealed brain temperature reductions after 60 min intranasal cooling with balloons circulated with saline at 20 °C in healthy and unsedated volunteers.
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| 2. |
- Covaciu, Lucian, et al.
(författare)
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Brain temperature in volunteers subjected to intranasal cooling
- 2011
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Ingår i: Intensive Care Medicine. - : Springer Science and Business Media LLC. - 0342-4642 .- 1432-1238. ; 37:8, s. 1277-1284
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Tidskriftsartikel (refereegranskat)abstract
- Intranasal cooling can be used to initiate therapeutic hypothermia. However, direct measurement of brain temperature is difficult and the intra-cerebral distribution of temperature changes with cooling is unknown. The purpose of this study was to measure the brain temperature of human volunteers subjected to intranasal cooling using non-invasive magnetic resonance (MR) methods. Intranasal balloons catheters circulated with saline at 20A degrees C were applied for 60 min in ten awake volunteers. No sedation was used. Brain temperature changes were measured and mapped using MR spectroscopic imaging (MRSI) and phase-mapping techniques. Heart rate and blood pressure were monitored throughout the experiment. Rectal temperature was measured before and after the cooling. Mini Mental State Examination (MMSE) test and nasal inspection were done before and after the cooling. Questionnaires about the subjects' personal experience were completed after the experiment. Brain temperature decrease measured by MRSI was -1.7 +/- A 0.8A degrees C and by phase-mapping -1.8 +/- A 0.9A degrees C (n = 9) at the end of cooling. Spatial distribution of temperature changes was relatively uniform. Rectal temperature decreased by -0.5 +/- A 0.3A degrees C (n = 5). The physiological parameters were stable and no shivering was reported. The volunteers remained alert during cooling and no cognitive dysfunctions were apparent in the MMSE test. Postcooling nasal examination detected increased nasal secretion in nine of the ten volunteers. Volunteers' acceptance of the method was good. Both MR techniques revealed brain temperature reductions after 60 min of intranasal cooling with balloons circulated with saline at 20A degrees C in awake, unsedated volunteers.
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| 3. |
- Covaciu, Lucian, et al.
(författare)
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Human brain MR spectroscopy thermometry using metabolite aqueous-solution calibrations
- 2010
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Ingår i: Journal of Magnetic Resonance Imaging. - : Wiley. - 1053-1807 .- 1522-2586. ; 31:4, s. 807-814
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To estimate absolute brain temperature using proton MR spectroscopy ((1)H-MRS) and mean brain-body temperature difference of healthy human volunteers. MATERIALS AND METHODS: Chemical shift difference between temperature-dependent water spectral line position and temperature-stable metabolite spectral reference was used for the estimations of absolute brain temperature. Temperature calibrations constants were obtained from the spectra of the N-acetyl aspartate (NAA line at approximately 2.0 ppm), glycero-phosphocholine (GPC line at approximately 3.2 ppm), and creatine (Cr line at approximately 3.0 ppm) aqueous solutions with pH values within physiologically pertinent ranges. Single-voxel PRESS sequence (TR/TE 2000/80 ms) was used for this purpose. Brain temperature was determined by averaging the temperatures computed from water-Cho, water-Cr, and water-NAA chemical shift differences. RESULTS: The mean brain temperature of 18 healthy volunteers was 38.1 +/- 0.4 degrees C and mean brain-body (rectal) temperature difference was 1.3 +/- 0.4 degrees C. CONCLUSION: Improved accuracy of the temperature constants and averaging the temperatures computed from water-Cho, water-Cr, and water-NAA chemical shift differences increased the reliability of the brain temperature estimations.
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| 4. |
- Covaciu, Lucian, 1964-
(författare)
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Intranasal Cooling for Cerebral Hypothermia Treatment
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The controlled lowering of core body temperature to 32°C to 34°C is defined as therapeutic hypothermia (TH). Therapeutic hypothermia has been shown to improve neurological outcome and survival in unconscious patients successfully resuscitated after cardiac arrest. Brain temperature is important for cerebral protection therefore methods for primarily cooling the brain have also been explored. This thesis focuses on the likelihood that intranasal cooling can induce, maintain and control cerebral hypothermia. The method uses bilaterally introduced intranasal balloons circulated with cold saline. Selective brain cooling induced with this method was effectively accomplished in pigs with normal circulation while no major disturbances in systemic circulation or physiological variables were recorded. The temperature gradients between brain and body could be maintained for at least six hours. Intranasal balloon catheters were used for therapeutic hypothermia initiation and maintenance during and after successful resuscitation in pigs. Temperature reduction was also obtained by combined intranasal cooling and intravenous ice-cold fluids with possible additional benefits in terms of physiologic stability after cardiac arrest. Rewarming was possible via the intranasal balloons. In these studies brain temperature was recorded invasively by temperature probes inserted in the brain. The fast changes in pig’s brain temperature could also be tracked by a non-invasive method. High-spatial resolution magnetic resonance spectroscopic imaging (MRSI) without internal reference showed a good association with direct invasive temperature monitoring. In addition the mapping of temperature changes during brain cooling was also possible. In awake and unsedated volunteers subjected to intranasal cooling brain temperature changes were followed by two MR techniques. Brain cooling was shown by the previously calibrated high-spatial resolution MRSI and by the phase-mapping method. Intranasal cooling reduced body temperature slightly. The volunteers remained alert during cooling, the physiological parameters stable, and no shivering was reported.
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| 5. |
- Covaciu, Lucian, et al.
(författare)
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Intranasal cooling with or without intravenous cold fluids during and after cardiac arrest in pigs
- 2010
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Ingår i: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172 .- 1399-6576. ; 54:4, s. 494-501
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Tidskriftsartikel (refereegranskat)abstract
- Background: Intranasal balloon catheters circulated with cold saline have previously been used for the induction and maintenance of selective brain cooling in pigs with normal circulation. In the present study, we investigated the feasibility of therapeutic hypothermia initiation, maintenance and rewarming using such intranasal balloon catheters with or without addition of intravenous ice-cold fluids during and after cardiac arrest treatment in pigs. Material and methods: Cardiac arrest was induced in 20 anaesthetised pigs. Following 8 min of cardiac arrest and 1 min of cardiopulmonary resuscitation (CPR), cooling was initiated after randomisation with either intranasal cooling (N) or combined with intravenous ice-cold fluids (N+S). Hypothermia was maintained for 180 min, followed by 180 min of rewarming. Brain and oesophageal temperatures, haemodynamic variables and intracranial pressure (ICP) were recorded. Results: Brain temperatures reductions after cooling did not differ (3.8 +/- 0.7 degrees C in the N group and 4.3 +/- 1.5 degrees C in the N+S group; P=0.47). The corresponding body temperature reductions were 3.6 +/- 1.2 degrees C and 4.6 +/- 1.5 degrees C (P=0.1). The resuscitation outcome was similar in both groups. Mixed venous oxygen saturation was lower in the N group after cooling and rewarming (P=0.024 and 0.002, respectively) as compared with the N+S group. ICP was higher after rewarming in the N group (25.2 +/- 2.9 mmHg; P=0.01) than in the N+S group (15.7 +/- 3.3 mmHg). Conclusions: Intranasal balloon catheters can be used for therapeutic hypothermia initiation, maintenance and rewarming during CPR and after successful resuscitation in pigs.
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| 6. |
- Covaciu, Lucian, et al.
(författare)
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Intranasal selective brain cooling in pigs
- 2008
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Ingår i: Resuscitation. - : Elsevier BV. - 0300-9572 .- 1873-1570. ; 78:1, s. 83-88
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Special clinical situations where general hypothermia cannot be recommended but can be a useful treatment demand a new approach, selective brain cooling. The purpose of this study was to selectively cool the brain with cold saline circulating in balloon catheters introduced into the nasal cavity in pigs. MATERIAL AND METHODS: Twelve anaesthetised pigs were subjected to selective cerebral cooling for a period of 6 h. Cerebral temperature was lowered by means of bilaterally introduced nasal balloon catheters perfused with saline cooled by a heat exchanger to 8-10 degrees C. Brain temperature was measured in both cerebral hemispheres. Body temperature was measured in rectum, oesophagus and the right atrium. The pigs were normoventilated and haemodynamic variables were measured continuously. Acid-base and electrolyte status was measured hourly. RESULTS: Cerebral hypothermia was induced rapidly and within the first 20 min of cooling cerebral temperature was lowered from 38.1+/-0.6 degrees C by a mean of 2.8+/-0.6 to 35.3+/-0.6 degrees C. Cooling was maintained for 6 h and the final brain temperature was 34.7+/-0.9 degrees C. Concomitantly, the body temperature, as reflected by oesophageal temperature was decreased from 38.3+/-0.5 to 36.6+/-0.9 degrees C. No circulatory or metabolic disturbances were noted. CONCLUSIONS: Inducing selective brain hypothermia with cold saline via nasal balloon catheters can effectively be accomplished in pigs, with no major disturbances in systemic circulation or physiological variables. The temperature gradients between brain and body can be maintained for at least 6 h.
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| 7. |
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| 8. |
- Lindgren, Erik, et al.
(författare)
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Gender differences in utilization of coronary angiography and angiographic findings after out-of-hospital cardiac arrest : A registry study
- 2019
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Ingår i: Resuscitation. - : Elsevier BV. - 0300-9572 .- 1873-1570. ; 143, s. 189-195
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: We investigated the impact of gender in performance and findings of early coronary angiography (CAG) and percutaneous coronary intervention (PCI), comorbidity and outcome in a large population of out-of-hospital cardiac arrest (OHCA) patients with an initially shockable rhythm.Methods: Retrospective cohort study. Data retrieved 2008-2013 from the Swedish Register for Cardio-Pulmonary Resuscitation, Swedeheart Registry and National Patient Register.Results: We identified 1498 patients of whom 78% were men. Men and women had the same pathology on the first registered electrocardiogram (ECG): 30% vs. 29% had ST-elevation and 10% vs. 9% had left bundle branch block (LBBB) (P=0.97). Proportions of performed CAG did not differ between genders. Among patients without ST-elevation/LBBB men more often had at least one significant stenosis, 78% vs. 54% (P= 0.001), more multi-vessel disease (P= 0.01), had normal coronary angiography less often, 22% vs. 46% and PCI more often, 59% vs. 42% (P= 0.03). Among patients without STelevation/LBBB on the initial ECG, more men had previously known ischaemic heart disease, 27% vs. 19% (P=0.02) and a presumed cardiac origin of the cardiac arrest, 86% vs. 72% (P< 0.001). Multivariable analysis showed no association between gender and evaluation by early CAG. In men and women, 1-year survival was 56% vs. 50% (P= 0.22) in patients with ST-elevation/LBBB and 48% vs. 51% (P= 0.50) in patients without.Conclusion: Despite no gender differences in ECG findings indicating an early CAG, men had more severe coronary artery disease while women more frequently had normal coronary angiography. However, this did not influence 1-year survival.
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| 9. |
- Nordmark, Johanna, et al.
(författare)
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Assessment of intravascular volume by transthoracic echocardiography during therapeutic hypothermia and rewarming in cardiac arrest survivors
- 2009
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Ingår i: Resuscitation. - : Elsevier BV. - 0300-9572 .- 1873-1570. ; 80:11, s. 1234-1239
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Tidskriftsartikel (refereegranskat)abstract
- AIM: To study haemodynamic effects and changes in intravascular volume during hypothermia treatment, induced by ice-cold fluids and maintained by ice-packs followed by rewarming in patients after resuscitation from cardiac arrest. MATERIALS AND METHODS: In 24 patients following successful restoration of spontaneous circulation (ROSC), hypothermia was induced with infusion of 4 degrees C normal saline and maintained with ice-packs for 26 h after ROSC. This was followed by passive rewarming. Transthoracic echocardiography was performed at 12, 24 and 48 h after ROSC to evaluate ejection fraction and intravascular volume status. Central venous pressure (CVP), central venous oxygen saturation (ScvO(2)) and serum lactate were measured. Fluid balance was calculated. RESULTS: Twelve hours after ROSC, two separate raters independently estimated that 10 and 13 out of 23 patients had a decreased intravascular volume using transthoracic echocardiography. After 24 and 48 h this number had increased further to 14 and 13 out of 19 patients and 13 and 12 out of 21 patients. Calculated fluid balance was positive (4000 ml the day 1 and 2500 ml day 2). There was no difference in ejection fraction between the recording time points. Serum lactate and ScvO(2) were in the normal range when echocardiography exams were performed. CVP did not alter over time. CONCLUSIONS: Our results support the hypothesis that inducing hypothermia following cardiac arrest, using cold intravenous fluid infusion does not cause serious haemodynamic side effects. Serial transthoracic echocardiographic estimation of intravascular volume suggests that many patients are hypovolaemic during therapeutic hypothermia and rewarming in spite of a positive fluid balance.
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| 10. |
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